The Pinch Test for Dreaming
"Pinch me, I must be dreaming!" What assumption about dreaming lies behind this saying? I see two main candidates:
(1.) If I'm dreaming and someone in the dream pinches me, I will wake.
(2.) If I think I might be dreaming and someone in the dream pinches me, I'll be able to tell whether I'm dreaming or not.
The more dominant and more plausible view, I suspect, is (2). The thought presumably is this: In dreams, we don't have tactile sense experiences, or pain experiences, or we do have such experiences but they're different from waking tactile experiences in a way discernible to a dreamer.
A plausible assumption, I said. And appealing, I think, to many contemporary Americans. But is it right? Let me mention one reason to think it might be, two reasons for doubt, and two questions.
Reason to think it might be: I've read a lot of dream reports in the course of my research on dreams (e.g. here), and indeed it's not unusual to remark on the absence of tactile and pain sensations in dreams. For example, someone might report dreaming of being stabbed in the stomach and seeing blood come out, but without feeling any pain.
Reason for doubt #1: Traditional theories of dreams, like Descartes's, as well as most contemporary theories of dreams, don't give us much reason to suppose that we'd experience vision and hearing in dreams (or have visual and auditory imagery) but not other senses.
Reason for doubt #2: In the 1950s, people thought they dreamed in black and white. Both before and after the 20th century, people generally report dreaming in color. The best explanation for this, I think, is not that our dreams themselves changed from color to black-and-white and back again, but rather that our reports about our dreams assimilate them too much to the dominant media of our culture. (There was even a brief period when some psychologists said our dreams were generally silent, like Charlie Chaplin films!) Hence I suspect that if the dominant media involved tactile sensations, our dream reports would include them.
Question 1: I know there is considerable cortical activity in visual areas during REM sleep (including in regions associated with color experience). Is there a lower level of activity in brain regions associated with pain and tactile sensation?
Question 2: Is the "pinch me" thing primarily just American, or anglophone, or confined to Western cultures, or is something like it widely cross-cultural? If we don't have tactile and pain experiences in sleep, one might suppose that the reasons for that would apply cross-culturally.